Alarm for pneumatic feeders.



PATEN TED JULY 26, 1904.

APPLICATION FILED OCT. 22, 1903.

2 SHEETS-SHEET 1.

N0 MODEL.

r J J a 9 5 I |1! E i 3 lllllI l l 1,1 L r 1 p NI! 2 E ll WitnessesAttorney PATENTED JULY 26, 1904.

T. J; ARNAULT.

ALARM FOB. PNEUMATIC PEEDERS.

APPLICATION FILED OUT. 22, 1903.

2 SHBETS'SHEBT 2.

N0 MODEL.

Witnesses Attorney Patented July 26, 1904.

UNITED STATES PATENT OFFICE.

THOMAS J. ARNAULT, OF EVERETT, WASHINGTON.

ALARM FOR PNEUMATIC FEEDERS.

SPECIFICATION forming part of Letters Patent No. 765,657, dated July 26,1904.

Application filed October 22, 1903. Serial No. 178,083. (No model.)

To all whom it may concern:

Be it known that I, THoMAs J ARNAULT, a citizen of the United States,residing at Everett, in the county of Snohomish and State of Washington,have invented certain new and useful Improvements in Alarms forPneumatic Feeders; and Ido declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

This invention relates to an alarm for pneumatic feeders of the kindemployed in connection with woodworking-machines in lumbermills andother woodworking establishments for feeding shavings, sawdust, andother refuse to the furnaces of the mill plant, to be employed as fuelfor generating steam in the boilers of said furnaces for driving saidplant, and particularly to means for indicating when the refuse-conduitbecomes choked, so that said conduit may be cleared and the fuelprevented from accumulating and taking fire in the conduit.

The object of the invention is to provide simple and effective alarm orindicating mechanism which is not liable to be rendered inactive byparticles of the fuel and which shall be of requisite sensitiveness andeificiency under all conditions of use.

With this and other objects in View the invention consists of certainnovel features of construction, combination, and arrangement of parts,as will be hereinafter more fully described, and particularly pointedout in the appended claims, reference being had to the accompanyingdrawings, in which Figure 1 shows in front elevation two boilerfurnaces,together with elements of the refuse-feeder, and my improved alarm orindicator, showing a portion of the conduit broken away at the junctionof the valve-chamber and branch pipes to expose the cut-01f apparatus.Fig 2 is a section, on an enlarged scale, through one of the branchpipes of the conduit and the casing of the indicator or alarm. Fig. 3 isan elevation of the same looking toward the switch-chamber, showing theclosure of the same removed; and Fig. 4: is a transverse section throughthe alarm-casing and alarm mechanism, taken substantially on the line 44 of Fig. 2.

Referring to the drawings, 1 designates a feed-pipe leading from thepoint of discharge of the shavings and sawdust or of the refuse, 2 ahopper into which the same discharges, and 3 a conduit extending fromthe hopper to the point where the refuse is to be used as fuel or storedfor future use. In the present instance I have shown this conduit 3bifurcated to provide branch pipes 4 and 5, leading to feed-openingscommunicating with the fireboxes of boiler-furnaces 6 and 7 to supplythe same with the refuse to be used as fuel.

Instead of connecting with the furnaces the conduit may connect with astorage house or vault in which the shavings or refuse may be stored forfuture use, or, if desired, an additional branch pipe may lead to astorage vault or house of this character, and the number of branch pipesmay be increased according to the number of furnaces and storage-housesto'be kept supplied with fuel. I do not limit myself-in this particular.to the application of the invention to the specific construction of feeddevice shown nor to a feed device of the character specified, as theinvention may be employed in connection with feed devices of any kind inwhich the feed of material is effected by pneumatic or otherfluid-pressure. The supply of fuel to the furnaces is governed by acut-off or regulating valve 8, disposed in a valve-chamber 9 at thepoint of junction of the hopper with the branch pipes 4 and 5, saidvalve controlling the supply of fuel to either or both branch pipes-atwill and being operated through the instrumentality of a loop, chain, orother flexible connection 10, attached to an arm 11, connected to saidvalve, passing through suitable guide-pulleys l2 and having at one end ahand-grip 13 for manually operating it in one direction and at theopposite end a counterweight 1e for automatically.

operating it in the reverse direction. Airthe refuse, owing toobstructions in the conduit or to the too rapid feed of the refuse tothe furnaces or storage-houses, resulting 1n.

the shutting down of the plant to allow the conduit to be cleared. Inorder to obviate this difliculty, I provide means for automaticallysounding an alarm for indicating when the conduit is becoming choked orthe refuse is feeding too rapidly or conditions are such that the feedof the refuse should be arrested in order to prevent the conduit fromchoking up. The means shown in the present instance for effecting thisresult comprises a pneumatic electric alarm governed by the pressure ofthe air within the conduit. In the present embodiment it consists of acasing 15, secured at some suitable point along the line of the conduit,said casing being shown in the present instance as connected to thebranch pipe 5. The front or inner side of the casing is suitably securedto said pipe and is provided with an opening in line with an opening inthe pipe, the opening in the casing being provided with a screen 16 toprevent any other than the very smallest particles of the fuel and dustfrom passing into said casing and interfering with the operation of theswitch of the alarm mechanism. The pipe 5 is provided above the openingtherein with a shield or deflector 17 which prevents the particles ofrefuse from coming in direct contact with and hanging in the meshes ofthe screen 16. The bottom of the casing 15 is secured to the pipe 5 alittle below the opening therein, leaving a portion of the pipeextending upward to form a flange or ledge 19, and in the casing 15 is amovable switch-controlling element consisting of'a plate or diaphragm18, which normally contacts with or closes against said flange or ledge19. The rear wall of the casing 15 has an opening 20, which permits airto enter to compensate for the movement of the said valve or diaphragm18, and it is also provided below said opening 20 with an opening 21,through which the dust and other fine particles which find their wayinto the casing 15 and become deposited upon the bottom thereof will beblown out by the blast when the member 18 is operated, thus clearing thecasing 15 of all foreign matter liable to interfere with the operationof the member 18. The opening 20 is primarily intended, however, as adischarge-opening to allow the air to pass out when the pipe 5 becomeschoked with refuse. I

The alarm mechanism actuated by the member 18 comprises an alarm-circuitincluding conductors 22 and 23, a battery 24 or other source of electricsupply, and a hell or other suitable alarm or indicating device 25. Inpractice this indicating device may be either an aural or a visualsignal, and I do not limit myself in this particular. The wires 22 and23 are connected to binding-posts 26 and 27,

which are in the form of bolts, each having a securing-nut 28. Thesebolts pass through openings in the top of a chamber 31 on one side ofthe casing 15 and through heads or disks 29 and 30, of rubber or otherinsulating material. said disks being arranged above and below the saidtop of the chamber. The openings in the to p of the chamber 31, throughwhich the bolts pass, are of such relative size that the, bolts do notcontact with the same, but are electrically insulated from each otherand from the casing and chamber by the said disks 29 and 30. To the headof the post 27 is pivoted a switch-arm 32, which is adapted to engagethe head of the binding-post 26,

and thereby close the said electric circuit to sound or operate thealarm device 25.

The switch-arm 32 is adapted to be operated by a contact head or knob33, of rubber or other insulating material, arranged upon one end of ashaft 3 1, journaled in the walls of the casing and chamber. This shaftalso carries the movable element 18, which is thus mounted to vibratetoward and from the screen-diaphragm 16. In this movement of the element18 the contact-knob 33 is operated to move the switch-arm 32 intocontact with the post 26 and permit it to be retracted by gravity. Inthe normal operation of the parts the element 18 closes air-tightagainst the frame 19 and the refuse under pressure of the blast feedsthrough the pipe 5 to the furnace or storage-house. When the furnacerequires fuel or the storage-house is unfilled, there is no impedimentto the free feed of the material and flow of air through the pipe 5; butwhen either the furnace or the storage-house becomes filled with fuel orthe pipe becomes choked there is a consequent resistance to the flow ofthe air and the further feed of the fuel or refuse, and this causes anaugmentation of pressure in the pipes, whereby the member 18, whichunder normal conditions is unaffected or but little affected by theblast, is forced outwardly and the air having no other vent escapesthrough the openings 21 and 22. In so doing whatever sediment or refusehas found its way into the casing 15 will be blown out, and theactuation of the part 18 will eflect the closing of the switch 32,thereby closing the electric circuit to sound the alarm, as hereinbeforedescribed. Upon the sounding of the alarm, which will be. located in thefurnace-room or at some point where it may be readily heard by theengineer or fireman, notice will be given of the choking of the conduit,so that the further feed of refuse may be arrested until the conduit isagain cleared out.

In the feed of the refuse to a storage-house it may happen that therewill be an augmentation of pressure in the pipe or conduit, especiallywhen there is a resistance from any cause to free exhaust of the airfrom the storage-house. Under such conditions unless this pressure isrelieved it will of course be understood that the alarm mechanism wouldbe operated. In-order to prevent the operation of the alarm mechanismfrom such a cause unless the resistance to the exhaust of air is sogreat as to cause a considerable augmentation of pressure in the conduitand interfere with the free feed of the refuse, I provide means forregulating the resistance to the movement of the part 18, to which end Iapply upon the opposite end of the shaft 34 from the contactknob 33 aweight 35, which is adjustable by means of a set-screw 36, to vary itsresistance to the turning of said shaft. Thus the alarm mechanism willremain unaffected until the pressure in the pipe or conduit reaches acertain predetermined point, thus preventing any unnecessary sounding ofthe alarm.

From. the foregoing description, taken in connection with theaccompanying drawings, the construction, operation, and advantages ofthe invention will be readily understood without requiring a moreextended explanation.

Various changes in the form, proportion, and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of the invention.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. A device for feeding material under airpressure, comprising, incombination, a feedconduit provided with an opening in its side, ascreen guarding said opening, a shield arranged upon the interior of theconductor and overhanging the near end of the screen in the path of thefeeding material to prevent direct contact of the body of the latterwith said screen, a box or chamber arranged upon the exterior of theconduit and in open communication with the same through said screen, avalve in said box or chamber adapted to swing outwardly upon adetermined augmentation of air-pressure in the conduit, the said box orchamber being provided in rear of said valve with upper and loweropenings for the admission and discharge of air and the discharge of anydust or fine particles of material which may enter the box or chamberthrough the screen, and an alarm actuated by the outward swingingmovement of the valve, substantially as described.

2. A device for feeding material under airpressure, comprising, incombination, a feedconduit provided with an opening in its side, ascreen guarding said opening, a shield arranged upon the interior of theconductor and overhanging the near end of the screen in the path of thefeeding material to prevent direct contact of the body of the latterwith said screen, a box or chamber arranged upon the ductors, aswitch-arm hinged or pivoted to one conductor and adapted to engage theother conductor, and a contact actuated by said shaft and adapted toengage and move said switch-arm, substantially as described.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

THOMAS J. ARNAULT.

Witnesses:

E. W. BUNDY, J. Y. KENNEDY.

